Alfred pongbatz



flakes,

Patented July 4, 1933 ALFRED PONGR'ATZ, 01] GRAZ, AUSTRIA, TO Fl "on BENEEA, or GENOA, ITALY PB'OCESS 0F IVIANUFACTURIIJ'G PEEYLEIJE TETBACJLHEGXYLIC ACID AIII-IYDRIDF No Drawing. Application filed March 1, 19129,

of the perylene series are ob iineu by treating diacetyl-dichloro perylene or dipropionyl dichloro perylene with cuprous cyanidoin suitable solvents. These do stul'i's which are diacyl-dinitril pc'rylenes are obtains; from diacyl-dihalogcn peryleuo having acyl group and a halogen atmn in ad acent peri position "ith metal cyunides in the presence of organic so-lventspsucli as quinolino or pyridine, separating the product of reaction from the said solvent and removing from this product the metallic constituent of metal cyanide. lh'eferably copper cyanide is user and the copper is removed from th reaction product by wash ng the same with aqueous ammonia. United States Patent 1,72%),- 596 dated August 20th,

Now the surprising discovery was made hat by oxidizing these dye stuffs perylone, totracarl'ioxylic acid may be obtained With an almost quantitative output.

A process is known by wh ch vat dye stuiis Example 1 1 part by Weight of the dye stuff cmisistin of diacetyl-dinitril perylene having an m y group and a nitril group in ad' acent pe osition and obtained in accoro: ice with E3 pie 1 of the above named application, is firstiy :[inoly suspended for instance y treating the same with concentrated sulphuric acid and subsequent precipitating with Water. The dye stuff is precipitated in reddish Violet To the suspension of 2.5 parts by Weight of a 20% solution or" sodium bichromate is added and the reactionis permitted to proceed at a temperature of about 90 centigrade. After 1 to 1% hours the oxidation is completed and the suspension has now a red colour and is anhydrous perylene totracarboxylic acid. It is very pure in the raw state already.

By re-precipitating from a dilute aqueous solution of caustic soda and dissolving in in ELL; nple 5343 854, and in .(lustria April 6, 19281 perylene is obtained.

The carbonyl groups oi? the acid are prob ably in the peri positions of the peryleno nucleus,

eane dye stuff as s liseiy SHFPCZIQGCl the same as l undis caused "o flow in 30 minutes at room temperatureand under continuous agitation into a solution of 1.5 parts by \VQiVllli oi potassium permanganatein 150 L by weip it of Water to which advantageously a little 7 inauganous sulphate added. The product of the reaction is identical with that obtained according to examnle l.

1 part by in Eunuple Ewdmple 3 1 part by weight of the dye stuff, consisting of dipropionyl-dinitril peryleno having an acyl and a nitrii group in adjacent peri position and obtained as above mentioned, is oxidized by means of potassium permanganate under the same conditions set forth in Example 2 with the difference however that in the case for the oxidation to anhydrous perylene totracurboxylie acid 2.5 parts by Weight of potassium permanganate are used.

, Although the individual reactions of the process are not yet absolutely ascertained,

. iructive distillation ofthlcicalcium they are most probably those illustrated by the following structural formula OH: H

| GI-NHz Oxidation HaC \\O/ The 3.9-dichloro-4L.1-O diacetyl-perylene Formula I, is converted by the reaction with copper cyanide and removal of the copper into the intermediate product, Formula 11, the CH groups being changed into CH groups and being combined the CNH groups which have been replaced for the Cl atoms. By the following oxidation with permanganate or bichromate the two CH=CNH groups are oxidized to OC=O groups thus giving perylene tetracarboxylic acid anhydride.

As is seen from the above example bichromates or permanganates are used as the oxidizing agents, that is to say salts of the oxygen acids of the group consisting of manganese and chromium.

the steps of dissolving diacyl-dinitril perylene having an acyl group and a nitril group in adjacent peri positions in sulphuric acid, precipitating the said diacyl-dinitril perylene from the solution by the addition of water and adding to the mixture so formed a salt of an oxygen acid of a group consisting of manganese and chromium capable of forming strongly oxidizing acids.

3. A process for manufacturing perylene tetracarboxylic acid anhydride comprising the steps of dissolving diacyl-dinitril perylene having an acyl group and a nitril group in adjacent peri position in sulphuric acid, precipitating the said diacyl-dinitril perylene fromthe solution by the addition of Water and adding to the mixture so formed an aqueous solution of a permanganate.

4:. A process for manufacturing perylene tetracarboxylic acid anhydride comprising the steps of dissolving diacyl-dinitril perylone having an acyl group and a nitril group in adjacent peri position in sulphuric acid, precipitating the said diacyl-dinitril perylene from the solution by the addition of Water and adding to th mixture so formed an aqueous solution of a permanganate and manganous sulphate.

In testimony whereof I have aflixed my sig nature.

ALFRED PONGRATZ. 

